Stupid Question on Tire Size and Speedo

[Ripper]

Stock Tundra's usually come with either 245/70-16 or 265/70-16 size tires.

There are a great number of larger size tires that can be put on a Tundra. Obviously the larger size of these tires causes the distance traveled by a single rotation of the tire to increase which in turn throws the speedo off.

Is there some way to reprogram the tire size so the speedo reads correct?

[PointCrossed]

Originally Posted by Ripper

Stock Tundra's usually come with either 245/70-16 or 265/70-16 size tires.

There are a great number of larger size tires that can be put on a Tundra. Obviously the larger size of these tires causes the distance traveled by a single rotation of the tire to increase which in turn throws the speedo off.

Is there some way to reprogram the tire size so the speedo reads correct?

I assume getting a larger or smaller gear for the end that goes in the tranny might fix that problem. Check with a performance store they might have a fix for that.

[Ripper]

Originally Posted by PointCrossed

I assume getting a larger or smaller gear for the end that goes in the tranny might fix that problem. Check with a performance store they might have a fix for that.

I was really hoping I could flip a switch or something else and program in the tire size. My $25 bicycle computer lets me do that. I guess there would always be the potential for abuse by programming in a small tire size so the odometer would rack up less miles than reality.

[PointCrossed]

Originally Posted by Ripper

I was really hoping I could flip a switch or something else and program in the tire size. My $25 bicycle computer lets me do that. I guess there would always be the potential for abuse by programming in a small tire size so the odometer would rack up less miles than reality.

Most auto Speedos are mechanical a cable with a wire that spins around inside that cable comes from the tranny to the speedo in the dash if you look right past the brake pedal you will see it going under the carpet from the dash the odometer part is digital and it works exactly like your bike computer except takes a reading from that cable and not the sensor on a wheel. hope I answered your stupid Question

[blm26]

From what I understand, the way you calibrate the speedo to a new tire size is actually inside the tranny. There is a set of small gears right at the tranny/speedo cable interface. By adjusting those gears, you can calibrate the speedo.

I know that is how some vehicles do it, but I cannot say for sure on the Tundra.

[PointCrossed]

Yep something like that.

[Hover]

Try searching the forums for "speedometer" or "speedo". A quick seach brought up this old thread: [Speedo Recalibration? ].

[prodigy]

You can take it to a speedo shop. Most city's have atleast one, and offer recailbration. I have had to do this on many cars and takles no more than 30 minutes and a small chunk of change.